Also unskip test that has already been fixed in f1b1ec70.

R=jgruber@chromium.org

Bug: v8:178
Change-Id: I9cd2156ef41146b0dd58a974088726f5cbda8058
Reviewed-on: https://chromium-review.googlesource.com/970243Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Yang Guo <yangguo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#52050}